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Process Control Daemon
Process Control Daemon (PCD) is an open source, light-weight system level Process management (computing), process manager/controller for Embedded Linux based projects (such as consumer electronics and network devices). This tool provides a complementary service for any Embedded Linux driven product and is specialized for the needs of Embedded system, embedded products. PCD was created because Embedded Linux distributions did not provide such a tool. Other similar tools which are available are not suited for embedded products in terms of compatibility, performance and limited hardware resources. Background The PCD project was designed and implemented by Hai Shalom, senior software engineer at Texas Instruments Israel at the time, as part of his M.Sc. degree in Computer Science. The project was initiated due to a true need in one of Texas Instruments’ broadband solutions (ARM11, ARM1176 Running MV-Linux Pro-5.00). The system was originally started with Bash script, shell scripts, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentralized software development model that encourages open collaboration. A main principle of Open-source software, open source software development is peer production, with products such as source code, blueprints, and documentation freely available to the public. The open source movement in software began as a response to the limitations of proprietary code. The model is used for projects such as in open source appropriate technology, and open source drug discovery. Open source promotes universal access via an open-source or free license to a product's design or blueprint, and universal redistribution of that design or blueprint. Before the phrase ''open source'' became widely adopted, developers and producers used a variety of other terms, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Domain Socket
A Unix domain socket (UDS), a.k.a. local socket, a.k.a. inter-process communication (IPC) socket, is a communication endpoint for exchanging data between processes executing in the same Unix or Unix-like operating system. The name, ''Unix domain socket'', refers to the domain argument value AF_UNIX that is passed to the function that creates a socket system resource. The same communication domain is also selected by AF_LOCAL. Valid type argument values for a UDS are: * SOCK_STREAM (compare to TCP) – for a stream-oriented socket * SOCK_DGRAM (compare to UDP) – for a datagram-oriented socket that preserves message boundaries (as on most UNIX implementations, UNIX domain datagram sockets are always reliable and don't reorder datagrams) * SOCK_SEQPACKET (compare to SCTP) – for a sequenced-packet socket that is connection-oriented, preserves message boundaries, and delivers messages in the order that they were sent The UDS facility is a standard component of a POSIX operatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LGPL
The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own (even proprietary) software without being required by the terms of a strong copyleft license to release the source code of their own components. However, any developer who modifies an LGPL-covered component is required to make their modified version available under the same LGPL license. For proprietary software, code under the LGPL is usually used in the form of a shared library, so that there is a clear separation between the proprietary and LGPL components. The LGPL is primarily used for software libraries, although it is also used by some stand-alone applications. The LGPL was developed as a compromise between the strong copyleft of the GNU General Public License (GPL) and more permissive licenses such as the BSD licenses and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Lesser General Public License
The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own (even proprietary) software without being required by the terms of a strong copyleft license to release the source code of their own components. However, any developer who modifies an LGPL-covered component is required to make their modified version available under the same LGPL license. For proprietary software, code under the LGPL is usually used in the form of a shared library, so that there is a clear separation between the proprietary and LGPL components. The LGPL is primarily used for software libraries, although it is also used by some stand-alone applications. The LGPL was developed as a compromise between the strong copyleft of the GNU General Public License (GPL) and more permissive licenses such as the BSD licenses and the MI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bus Error
In computing, a bus error is a Trap (computing), fault raised by hardware, notifying an operating system (OS) that a process is trying to access computer data storage, memory that the Central processing unit, CPU cannot physically address: an invalid address for the address bus, hence the name. In modern use on most architectures these are much rarer than segmentation faults, which occur primarily due to memory access violations: problems in the logical address, ''logical'' address or permissions. On POSIX-compliant platforms, bus errors usually result in the SIGBUS signal being sent to the process that caused the error. SIGBUS can also be caused by any general device fault that the computer detects, though a bus error rarely means that the computer hardware is physically broken—it is normally caused by a Software bug, bug in computer program, software. Bus errors may also be raised for certain other paging errors; see below. Causes There are at least three main causes of bus er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segmentation Fault
In computing, a segmentation fault (often shortened to segfault) or access violation is a Interrupt, failure condition raised by hardware with memory protection, notifying an operating system (OS) the software has attempted to access a restricted area of memory (a memory access violation). On standard x86 computers, this is a form of general protection fault. The operating system kernel (operating system), kernel will, in response, usually perform some corrective action, generally passing the fault on to the offending Process (computing), process by sending the process a signal (IPC), signal. Processes can in some cases install a custom signal handler, allowing them to recover on their own,''Expert C programming: deep C secrets'' By Peter Van der Linden, page 188 but otherwise the OS default signal handler is used, generally causing abnormal termination of the process (a program Crash (computing), crash), and sometimes a core dump. Segmentation faults are a common class of error i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gdbserver
gdbserver is a computer program that makes it possible to remotely debug other programs. Running on the same system as the program to be debugged, it allows the GNU Debugger to connect from another system; that is, only the executable to be debugged needs to be resident on the target system ("target"), while the source code and a copy of the binary file to be debugged reside on the developer's local computer ("host"). The connection can be either TCP or a serial line. How it works # gdbserver is launched on the target system, with the arguments: #* Either a device name (to use a serial line) or a TCP hostname and port number, and #* The path and filename of the executable to be debugged #:It then waits passively for the host gdb to communicate with it. # gdb is run on the host, with the arguments: #* The path and filename of the executable (and any sources) on the host, and #* A device name (for a serial line) or the IP address and port number needed for connection to the target ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daemon (computer Software)
In computing, a daemon is a program that runs as a background process, rather than being under the direct control of an interactive user. Customary convention is to name a daemon process with the letter ''d'' as a suffix to indicate that it's a daemon. For example, is a daemon that implements system logging facility, and is a daemon that serves incoming SSH connections. Even though the concept can apply to many computing systems, the term ''daemon'' is used almost exclusively in the context of Unix-based systems. In other contexts, different terms are used for the same concept. Systems often start daemons at boot time that will respond to network requests, hardware activity, or other programs by performing some task. Daemons such as cron may also perform defined tasks at scheduled times. Terminology In the context of computing, the word is generally pronounced either as or . The term was coined by the programmers at MIT's Project MAC. According to Fernando J. Corbat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Process Management (computing)
A process is a program in execution, and an integral part of any modern-day operating system (OS). The OS must allocate resources to processes, enable processes to share and exchange information, protect the resources of each process from other processes and enable synchronization among processes. To meet these requirements, The OS must maintain a data structure for each process, which describes the state and resource ownership of that process, and which enables the operating system to exert control over each process. Multiprogramming In any modern operating system, there can be more than one instance of a program loaded in memory at the same time. For example, more than one user can be executing the same program, with each user having separate copies of the program loaded into memory. With some programs, it is possible to have one copy loaded into memory, while several users have shared access to it so that they can each execute the same program-code. Such a program is called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
